How many solutions does this linear system have

y = 2x - 5

-8x - 4y = -20

replace the 1st equation into the 2nd one for y

-8x-4(2x-5) = -20

-8x-8x+20 =-20

-16x+20 = -40

-16x=-40

x = 5/2 = 2.5

y = 2x-5 - 2(2.5) - 5 = 5-5 = 0

one solution (2.5,0)

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.